This is a demo of my Random Environment System that can be used in any Unity project. The demo includes Unity's Bootcamp demo with random weather, and a scene made with Unity's ShantyTown assets showing random weather and object "generation".

The scripts use "Transform" variables that are for the objects that you want to use in your scene. How random weather is supposed to work is you have empty's with skyboxes, sound effects, and different props (which can be randomized with the random object system) with it's active property set to false. The objects are then set to active based on a random number generated through the script. If that doesn't make any sense to you, that's okay. Reading over this, I can see it's pretty hard to understand. Just play around with the scripts and play the demo to fully understand how it's intended to work.